lecture 13 & 14: pathogenicity of microorganisms

Question 1

define parasites

Answer 1

organisms that live on or within a host organisms and are metabolically dependent on the host. or any organism that cause disease

Question 2

define host

Answer 2

larger organism that supports the survival and growth of a smaller organism

Question 3

define infection

Answer 3

a parasite growing and multiplying within/on a host.

Question 4

define primary (frank) pathogen)

Answer 4

causes disease by direct interaction with healthy host

Question 5

define opportunistic pathogen

Answer 5

may be part of normal flora and causes disease when it has gained access to other tissue sites or host is immunocompromised

Question 6

chain of events for a successful infection

Answer 6

agent identity, virulence of agent, means of exposure to agent, dose of agent, susceptibility of host to agent

Question 7

define an infection passed form animal to human

Answer 7

zoonoses

Question 8

define reservoir

Answer 8

natural environmental location in which the pathogen normally resides

Question 9

define vector

Answer 9

organisms that spread disease from one host to another

Question 10

define signs

Answer 10

objective changes in body that can be directly observed

Question 11

define symptoms

Answer 11

subjective changes experienced by patient

Question 12

define disease syndrome

Answer 12

set of characteristic signs of symptoms

Question 13

define incubation period

Answer 13

period after pathogen entry, before signs and symptoms

Question 14

define prodromal stage

Answer 14

onset of signs and symptoms (not clear enough for diagnosis)

Question 15

define period of illness

Answer 15

disease is most severe, signs and symptoms

Question 16

define covalescence

Answer 16

signs and symptoms begin to disappear

Question 17

define virulence factors

Answer 17

allow a pathogen to outcompete host cells and resist their defenses

Question 18

define pathogenicity islands

Answer 18

major virulence factors on large segments on chromosomal or plasmid DNA

Question 19

what are the steps of adherence and colonization

Answer 19

entrance and attachment –> portal of entry –> adherence –> colonization

Question 20

how do pili or fimbriae adhere

Answer 20

bind complementary receptor sites on host cell surface

Question 21

define colonization

Answer 21

site of microbial reproduction on/in host

Question 22

what is an example of something that uses glycocalyx

Answer 22

Streptococcus mutans

Question 23

what is an example of something that uses fimbriae

Answer 23

E. coli

Question 24

what is an example of something that uses M protein

Answer 24

Streptococcus pyogenes

Question 25

what is an example of something that uses F protein

Answer 25

S. pyogenes

Question 26

what organism has product coagulase

Answer 26

S. aureus

Question 27

what organism has product hyaluronidase

Answer 27

groups A, B, C and G streptococci, staphylococci, clostridia

Question 28

what organism has product leukocidins

Answer 28

staphylococci, pneumococci, and other streptococci

Question 29

define bacteremia

Answer 29

presence of viable bacteria in the blood

Question 30

define septicemia

Answer 30

pathogens or their toxins in the blood

Question 31

what part of the AB exotoxin is responsible for the toxic effect

Answer 31

A subunit

Question 32

how do endotoxins bring about its effects

Answer 32

indirectly (interacts with host molecules and cells, activating host systems)

Question 33

define mycotoxins

Answer 33

secondary metabolites of fungi

Question 34

what mycotoxins do A. flavus and A. parasiticuc produce

Answer 34

carcinogenic aflatoxin

Question 35

what mycotoxins does stachybotrys produce

Answer 35

tissue-damaging satratoxins

Question 36

what mycotoxins does Claviceps purpurea produce

Answer 36

LSD

Question 37

what do M proteins do

Answer 37

resists phagocytosis

Question 38

what do Opa proteins do

Answer 38

inhibit T helper cells

Question 39

what does my colic acid do

Answer 39

resists digestion

Question 40

what is an example of a bacteria that uses opa protein

Answer 40

Neisseria gonorrhoeae

Question 41

what is an example of a bacteria that uses mycolic acid

Answer 41

mycobacterium tuberculosis

Question 42

what do capsules do

Answer 42

prevent phagocytosis

Question 43

what are some types of bacteria that use capsules

Answer 43

S. pneumoniae, haemophillis influenzae, bacillus anthracis

Question 44

what does coagulase do

Answer 44

coagulates fibrinogen

Question 45

what do kinases do

Answer 45

digest fibrin clots

Question 46

what does hyaluronidase do

Answer 46

hydrolyzes hyaluronic acid

Question 47

what does collagenase do

Answer 47

hydrolyzes collagen

Question 48

what do IgA proteases do

Answer 48

destroy IgA antibodies

Question 49

what are some ways to get contact transmission

Answer 49

direct contact, indirect contact, droplet spread

Question 50

define fomites

Answer 50

common vehicles such as surgical instruments, bedding and eating utensils

Question 51

define external (mechanical) transmission

Answer 51

passive carriage of pathogen on body of vector (no growth of pathogen during transmission)

Question 52

define internal transmission

Answer 52

carried within vector

Question 53

define harborage transmission

Answer 53

type of internal transmission-pathogen does not undergo changes within vector

Question 54

define biologic transmission

Answer 54

type of internal transmission-pathogen undergoes changes within vector

Question 55

when does vertical transmission occur

Answer 55

when the unborn child acquires a pathogen from an infected mother

Question 56

what are the 2 main factors of host susceptibility

Answer 56

defense mechanisms of host and pathogenicity of pathogen